But all the breathability, zips and vents in the world won't make it cool enough to wear over a certain temperature. For me, it's between 50 and 55. Any warmer, and I get wetter from sweat inside the coat than I do from rain by not wearing it. Sure I'd make less heat if I slowed down...
So today my rain jacket stayed home, and it will tomorrow too.
That's where a rain cape will work. I have been using it a lot lately. Temps over 50, heavy rain and I'm trying not to show up at my destination a soggy mess. It is admittedly pretty useless for the shoes, but it does keep the gloves dry. It has a hood, but that increases heat enormously.
I find it OK to arrive with a soggy head, but dry shirt. gloves and shorts. If it is really raining, I sometimes put the hood under the helmet.
Just be careful in heavy wind...